1. Field of the Invention
The present invention relates to a medical manipulator system by which a predetermined working unit performs movements and operations based on operation commands input from an operating unit.
2. Description of the Related Art
In laparoscopic surgery, a number of small holes are opened in a patient's abdomen or the like, and an endoscope, a forceps (or manipulator) or the like is inserted, and surgery is carried out while the surgeon observes an image from the endoscope on a monitor. In this type of laparoscopic surgery, owing to the fact that opening of the abdominal cavity is unnecessary, the burden on the patient is small, and number of days for the post-operative recovery and number of days spent in the hospital can be significantly reduced. Therefore, laparoscopic surgical operations are expected to find an increased range of applications.
A manipulator system, for example, as disclosed in Japanese Laid-Open Patent Publication No. 2004-105451, comprises a manipulator main body, and a controller for controlling the main body. The manipulator main body comprises an operating unit, which is operable by hand, and a working unit, which is detachable and exchangeable with respect to the operating unit.
The working unit (tool) includes an elongate connecting shaft, and a distal end working unit (also referred to as an “end effector”) disposed at the end of the connecting shaft. One or more actuators (motors) are disposed in an operating unit for driving the distal end working unit by means of wires. The wires are trained around pulleys at a base end side. The controller drives the motors disposed in the operating unit, and also drives the wires in an advancing/retracting manner via the pulleys.
Because of the necessity to easily clean and disinfect the working unit periodically, the working unit does not contain any electronic components such as sensors or the like, and the positions and origin points of the distal end working unit and the base end pulleys cannot be detected directly. Rather, a structure is provided in which the axial positions (posture) of the distal end working unit are calculated based on a rotation amount of the motors.
Incidentally, in laparoscopic surgery, various different types of working units are used depending on the surgery involved. A gripper, a cutter, an electrical knife, an ultrasonic knife, a surgical drill, or the like may be given as examples thereof. Such working units are disposed detachably with respect to the operating unit, and a structure is provided, such that when installed, the pulleys on the base end side of the working unit engage with rotary axes of the motors disposed in the operating unit.
In this manner, in the case of a system, which is predicated on enabling the connection of multiple different types of working units with respect to a single operating unit, it is necessary to set the motor phases such that all of the working units can be attached and detached while maintaining a sole common axial-positioning thereof (see, e.g., Japanese Laid-Open Patent Publication No. 2004-105451). Such axial positioning is referred to as an origin point (or an initial position).
Further, when it is desired to exchange the distal end working unit with another type, it is advisable also to exchange the manipulator main body. In this case, a connector, which connects the controller and the operating unit of the manipulator main body, is disconnected, and another connector of a different manipulator main body is reconnected.
With general manipulators available in the industry, although the manipulator and the controller are not disconnected (cut off) while the system is in use (i.e., during system operation), for medical use, it is preferable for detachment (cutting off) between the manipulator and the control apparatus to be easily carried out, since as indicated above, multiple different types of working units are utilized with the manipulator.
The following may be cited as conventional techniques concerning manipulator control systems: Japanese Laid-Open Patent Publication No. 2004-105451, Japanese Laid-Open Patent Publication No. 2004-208922, and U.S. Pat. No. 6,331,181.
Japanese Laid-Open Patent Publication No. 2004-105451 proposes a structure in which it is unnecessary to consider switching of the motor excitation or electrical configurations at the time of detachment.
Japanese Laid-Open Patent Publication No. 2004-208922 discloses features related to electrical detachment of plural end tools (working units).
According to U.S. Pat. No. 6,331,181, in relation to attachment and detachment of a medical manipulator, a circuit is included in a front-end manipulator for extracting an ID, wherein controls are carried out by the control apparatus based on obtaining such information.
Incidentally, as described above, the axial positioning of the distal end working unit is calculated taking as a standard the origin point thereof, for example. Accordingly, in the case that the working unit is exchanged during an operation, it is essential for the axial positioning of the newly installed and different working unit to match with the origin point accurately. Stated otherwise, when the working unit is separated from the operating unit, it is desirable that the working unit be placed in an axial position that matches with the origin point thereof. In particular, when the manipulator is in an operational mode, caution must be taken so that the connector that connects the operating unit and controller of the manipulator cannot be pulled out.
Further, in the event that the distal end working unit of the manipulator is to be taken out of the body, it is necessary to halt the operations thereof beforehand. For this purpose, based on a switching operation or the like in the controller, both an operational mode in which the motors are driven, and a stopped mode in which the motors are halted irrespective of whether operations of the operating unit are present or not, are provided, wherein preferably the control is carried out by distinguishing between these modes. Based on such switching operations or the like, preferably, the operator can easily confirm switching between the operational mode and the stopped mode.